Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754892AbZCYXqW (ORCPT ); Wed, 25 Mar 2009 19:46:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751670AbZCYXqO (ORCPT ); Wed, 25 Mar 2009 19:46:14 -0400 Received: from out2.smtp.messagingengine.com ([66.111.4.26]:54478 "EHLO out2.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751006AbZCYXqN (ORCPT ); Wed, 25 Mar 2009 19:46:13 -0400 Date: Thu, 26 Mar 2009 10:46:04 +1100 From: Bron Gondwana To: Linus Torvalds Cc: Theodore Tso , David Rees , Jesper Krogh , Linux Kernel Mailing List Subject: Re: Linux 2.6.29 Message-ID: <20090325234604.GA14828@brong.net> References: <49C87B87.4020108@krogh.cc> <72dbd3150903232346g5af126d7sb5ad4949a7b5041f@mail.gmail.com> <49C88C80.5010803@krogh.cc> <72dbd3150903241200v38720ca0x392c381f295bdea@mail.gmail.com> <20090325183011.GN32307@mit.edu> <20090325220530.GR32307@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: brong.net User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1064 Lines: 27 On Wed, Mar 25, 2009 at 04:23:08PM -0700, Linus Torvalds wrote: > > > On Wed, 25 Mar 2009, Theodore Tso wrote: > > > > > > The problem being that unlike the ratio, there's no sane default value > > > that you can at least argue is not _entirely_ pointless. > > > > Well, if the maximum time that someone wants to wait for an fsync() to > > return is one second, and the RAID array can write 100MB/sec > > How are you going to tell the kernel that the RAID array can write > 100MB/s? > > The kernel has no idea. Not at boot up, but after it's been using the RAID array for a little while it could... Bron (... imagining a tunable "max_fsync_wait_target_centisecs = 100" which caused the kernel to notice how long flushes were taking and tune its buffer sizes to be approximately right over time ) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/